Question

The students were given several minerals and a Mohs hardness scale. The students then investigated which minerals could scratch the others. The table shows the Mohs hardness scale, which is used to test the hardness of minerals.

Mineral Mohs Hardness
Talc 1
Gypsum 2
Calcite 3
Fluorite 4
Apatite 5
Feldspar 6
Quartz 7
Topaz 8
Corundum 9
Diamond 10
Using the scale, select the mineral that is described in each row.

Gypsum Fluorite Topaz Quartz
Can be scratched by Diamond but not Quartz




Can be scratched by Fluorite but not Talc




Can be scratched by Topaz but not Feldspar




Can be scratched by Feldspar but not Calcite

Answer 1

Answers:
1) Topaz
2) Gypsum
3) Quartz
4) Fluorite

Brief reasoning:
- Diamond (10) but not Quartz (7) → hardness >7 and <10 → Topaz (8).
- Fluorite (4) but not Talc (1) → hardness >1 and <4 → Gypsum (2).
- Topaz (8) but not Feldspar (6) → hardness >6 and <8 → Quartz (7).
- Feldspar (6) but not Calcite (3) → hardness >3 and <6 → Fluorite (4).